4. Tabernaemontana divaricata (Linnaeus) R. Brown ex Roemer & Schultes, Syst. 4: 427. 1819.
狗牙花 gou ya hua
Nerium divaricatum Linnaeus, Sp. Pl. 1: 209. 1753; Ervatamia coronaria (Jacquin) Stapf; E. divaricata (Linnaeus) Burkill; E. flabelliformis Tsiang; N. coronarium Jacquin; Tabernaemontana coronaria (Jacquin) Willdenow; T. flabelliformis (Tsiang) P. T. Li.
Shrubs or small trees 0.5-5 m tall, glabrous. Petiole 3-10 mm; leaf blade elliptic or narrowly so, 3-18 X 1-6 cm, apex acuminate; lateral veins 5-17 pairs. Cymes dichotomous, 1-8-flowered; bracts scalelike. Flower buds with an ovoid head, apex acute or obtuse. Calyx lobes often ciliate. Corolla white, tube 1.5-2.7 cm; lobes simple or double, obovate or broadly so, 1.5-2.7 X 0.8-2 cm. Stamens inserted at basal third of corolla tube. Follicles obliquely and narrowly ellipsoid, 2-7 X 0.6-1.5 cm. Fl. Apr-Sep, fr. Jul-Nov. 2n = 22*.
Montane brushwoods, sparse forests; 100-1600 m. S Yunnan (cultivated in Fujian, Guangdong, Guangxi, Hainan, Taiwan, Yunnan) [Bangladesh, Bhutan, India, Myanmar, Nepal, Thailand; cultivated in tropical and subtropical Asia].
All parts of the plant are poisonous. The roots, leaves, and flowers are used in Guangdong and Guangxi against snake and scorpion poisoning. In modern medicine, the roots are used to treat hypertension, headache, and scabies.